1. Field of the Invention
The present invention relates to a stator of an electric rotating machine, especially an electric rotating machine mounted on a passenger car, a truck or the like.
2. Description of Related Art
Generally, as described, for example, in French Patent No. 2869736, a stator of a vehicle-use electric rotating machine is provided with an insulating sheet for insulation between electrical conductors (a stator coil) and a stator core thereof. The insulating sheet is formed with holes at a half area thereof so that the stator coil can be adhered to the insulating sheet by filling impregnating varnish around the stator coil.
In the stator disclosed in the above patent document, since the stator coil is constituted of round wires as electric conductors, there are a lot of inter-conductor spaces. Accordingly the impregnating varnish can easily enter between the electric conductors. However, there is very little clearance between the slot side-wall (the inner side wall of each slot formed in the stator core) and the insulating sheet. Accordingly, since very little impregnating varnish can enter between the slot side-wall and the insulating sheet even when the insulating sheet is formed with holes, the adhering strength between the insulating sheet and the stator coil is insufficient. Accordingly, there is a concern that the insulating sheet and the electric conductors move within each slot especially for the case of a high power vehicle-use alternator in which a large force is applied to its stator coil.